The current El Nino, which could be strongest in history, is likely to trigger cyclones moving westwards towards Tamil Nadu and Andhra Pradesh in the post monsoon months, Joseph PV, former director of India Meteorological Department (IMD) said.

The El Nino of 2015 has adversely impacted the monsoon rainfall in India and the side effects of warming of the surface temperature of north Indian Ocean is strongly correlated with active cyclones with a pre -dominant westward motion, he added.

According to the latest report from the World Meteorological Organisation (WMO), the current El Nino event is “mature and strong” and will continue to strengthen through the end of the year, with temperatures rivaling the strongest El Nino events in recorded history. As a significant portion of the ocean warms to above-average temperatures, the cross-Pacific trade winds slow and strong patterns of clouds and heavy rain begin to develop near the International Date Line disrupting weather patterns all over the world. Meteorologists from WMO say El Nino has already served to lower the South Asian monsoon season.

“The all-India rainfall from June 1 to September 23 is 12% less than the normal. From the last week of June to mid-July and again during the whole of August and during the first half of September, the daily rainfall was less than normal. Such prolonged spells of subdued Indian rainfall is a characteristic of a large percentage of the El Nino,” Joseph, now professor emeritus in the atmospheric science department at Cochin University of Science and Technology, told FE.